J2ME欢迎界面代码.doc

J2ME欢迎界面的代码目 录方法一1【1】功能1【2】代码1【3】运行截图3运行正常的3运行出错的4方法二5【1】功能5【2】代码6【3】运行截图8运行正常的8运行出错的9方法一【1】功能显示欢迎界面，按任意键进入系统，按退出键，退出程序。【2】代码文件名：welcomeMidlet.javapackage test;import javax.microedition.lcdui.Alert;import javax.microedition.lcdui.AlertType;import javax.microedition.lcdui.Canvas;import javax.microedition.lcdui.Command;import javax.microedition.lcdui.CommandListener;import javax.microedition.lcdui.Display;import javax.microedition.lcdui.Displayable;import javax.microedition.lcdui.Form;import javax.microedition.lcdui.Graphics;import javax.microedition.lcdui.Image;import javax.microedition.midlet.MIDlet;import javax.microedition.midlet.MIDletStateChangeException;public class WelcomeMidlet1 extends MIDlet implements CommandListenerprivate Display display;private Image bgImage = null;private Form frm = new Form(This is a test.);private Command cmdOk = new Command(确定,Command.OK,1);private Command cmdExit = new Command(退出,Command.EXIT,2);private boolean imgexit = true;/图片存在private WelcomeCanvas wc = new WelcomeCanvas();private Alert AlertError = new Alert(错误,资源文件不存在！,null,AlertType.ERROR); /标题、屏幕显示内容、提示图片、错误类型public WelcomeMidlet1()/先初始化欢迎界面的背景图片 try bgImage = Image.createImage(/welcome2.gif); catch (Exception e) e.printStackTrace();System.out.println(IOException错误，图片文件不存在); imgexit = false;/图片不存在protected void startApp() throws MIDletStateChangeException display = Display.getDisplay(this);if(imgexit)/图片存在，进入欢迎界面 display.setCurrent(wc); wc.setTitle(请任意键进入系统。); wc.addCommand(cmdExit); wc.setCommandListener(this);else/图片不存在，提示出错信息AlertError.setTimeout(Alert.FOREVER);display.setCurrent(AlertError);AlertError.addCommand(cmdExit);AlertError.setCommandListener(this);public class WelcomeCanvas extends Canvas public WelcomeCanvas() protected void paint(Graphics g) /绘制背景图片 g.drawImage(bgImage,this.getWidth()/2-bgImage.getWidth()/2,this.getHeight()/2-bgImage.getHeight()/2,Graphics.TOP | Graphics.LEFT); protected void keyPressed(int keyCode) /按下任意键后，转到需要显示的界面 display.setCurrent(frm); frm.addCommand(cmdOk); public void commandAction(Command c,Displayable d)if(c=cmdExit)/退出this.notifyDestroyed();protected void destroyApp(boolean arg0) throws MIDletStateChangeException protected void pauseApp() / TODO Auto-generated method stub【3】运行截图运行正常的按退出键则退出程序，按其他任意键，则进入如下界面：运行出错的改变图片名，改为一个不存在的名字，则运行效果如下：方法二【1】功能显示开机界面后，按退出键退出程序，若什么也不做，等待3秒后自动跳转到另一界面。【2】代码文件名：WelcomeMidlet2.javapackage test;import javax.microedition.lcdui.Alert;import javax.microedition.lcdui.AlertType;import javax.microedition.lcdui.Canvas;import javax.microedition.lcdui.Command;import javax.microedition.lcdui.CommandListener;import javax.microedition.lcdui.Display;import javax.microedition.lcdui.Displayable;import javax.microedition.lcdui.Form;import javax.microedition.lcdui.Graphics;import javax.microedition.lcdui.Image;import javax.microedition.midlet.MIDlet;import javax.microedition.midlet.MIDletStateChangeException;public class WelcomeMidlet2 extends MIDlet implements CommandListenerprivate Display display;private Image bgImage = null;private Form frm = new Form(This is a test.);private Command cmdOk = new Command(确定,Command.OK,1);private Command cmdExit = new Command(退出,Command.EXIT,2);private boolean imgexit = true;/图片存在private WelcomeCanvas wc ;private Alert AlertError = new Alert(错误,资源文件不存在！,null,AlertType.ERROR);/标题、屏幕显示内容、提示图片、错误类型public WelcomeMidlet2()/先初始化欢迎界面的背景图片 try bgImage = Image.createImage(/welcome.gif); catch (Exception e) e.printStackTrace();System.out.println(IOException错误，图片文件不存在); imgexit = false;/图片不存在protected void startApp() throws MIDletStateChangeException display = Display.getDisplay(this);if(imgexit)/图片存在，进入欢迎界面 wc = new WelcomeCanvas(); display.setCurrent(wc); wc.setTitle(请等待，3秒后自动进入系统。); wc.addCommand(cmdExit); wc.setCommandListener(this);else/图片不存在，提示出错信息AlertError.setTimeout(Alert.FOREVER);display.setCurrent(AlertError);AlertError.addCommand(cmdExit);AlertError.setCommandListener(this);public class WelcomeCanvas extends Canvas implements Runnable public WelcomeCanvas() Thread thread = new Thread(this); thread.start(); protected void paint(Graphics g) /绘制背景图片 g.drawImage(bgImage,0,0,Graphics.TOP | Graphics.LEFT); public void run() try /等待3秒 Thread.sleep(3000); catch(Exception e) e.printStackTrace(); System.out.println(线程休眠出错); /显示需要显示的界面 display.setCurrent(frm); frm.addCommand(cmdOk); public void commandAction(Command c,Displaya